Anyone know where i need to go to get my cat's microchip information changed?

I rescued him from a friend of mine that abused animals. We are no longer friends. Anyway i wasn't too worried about it until he actually got outside. It was completely an accident but i came home one day and he was freaking out screaming to get back in on the front porch. He does have a flea collar on.

Anyway, if he got lost now he'd go back to the person i rescued him from and i dont trust her with him.

Step 1 - put an actual collar and standard ID tag on the cat with your phone number and addy if you can fit the addy. My cat has both a microchip and standard ID. That way if someone findsmy cat if she ever gets out they can return her directly to me as long as she hasn't lost the first tag/collar.

Step 2- Find out the tag brand, although Home Again as mentioned above *is* used a lot around here, and go through their process to change the tag.

*however* depending on where she got the cat from, there may have been a clause in the adotpion that the cat cannot be given away to someone else. it has to be returned to the shelter. not sure if that wouldl cause any issues in getting the name on the chip changed. Although address changes for the same name aren't usually a huge issue.